Pin art matrix devices have been popular as toys and as art for a number of years. FIG. 1 shows a typical pin art matrix device. The device takes a three-dimensional relief of a surface by using a crowded array of pins 2 that are free to slide back and forth independently. The three dimensional object, such as a human hand, is pressed into the under side of the matrix 4 and the pins 2 traverse upwards proportional to the contours of the object. The object is then displayed on the top side 6 of the matrix as a combination of pins all at various heights.
Tactile displays for the sight impaired have also been around for a number of years which take advantage of pin matrix devices. Typically the matrix is fairly small and actuators raise a series of pins to a same height to represent a braille character which may be read by touching a finger to the matrix. Each braille character or cell is made up of six dot positions, arranged in a rectangle matrix containing two columns of three dots each. A dot may be raised at any of the six positions to form sixty-four combinations, including the combination in which no dots are raised.
More recently devices have been developed for translating visual images into tactile images. For example, U.S. published patent application 2002/0158836 to Ishmael, Jr. et al., describes an imaging device for converting incident light from a visual image into electrical signals that are proportional to the gray scale intensity of the incident light. A tactile display device has a two-dimensional array of variable height pixels, wherein the height of each pixel in the tactile display is dynamically variable in proportion to the electrical signals.